Originally posted by Nereid
Um, there is an interesting difficulty being assumed away here. Leave aside whether mainstream science can 'believe' anything; let's say you wished to study, using the scientific method, 'life in non-Earth environments'. How would you go about it?
a) Find some life in non-Earth environments and study it?
b) go to non-Earth environments and look for life?
c) take Earth life to a non-Earth environment and see what happens?

Turn the question around; how would you go about testing - using the scientific method - the following ideas (suitably reworded so they were hypotheses)?
1) non-Earth life thrives in the cores of neutron stars
2) non-Earth life has a characteristic time of 40 million years
3) dark matter creatures inhabit ecosystems which we call rich galaxy clusters.

My response is:

Points "a" and "b" are perfectly acceptable, in principle, and point "c" doesn't make much sense, since Earth-like life needn't be able to survive in non-Earth environment for non-Earth-like life to survive there. Remember life evolves to fit its own environment...it wouldn't make much sense to expect to find Earth-like life on a Jupiter-like planet, but that doesn't mean that there is no life at all.

As to points 1, 2, and 3, I don't understand why any of these need to be the case for there to be non-Earth-like life in the Universe.

Originally posted by Nereid
What other sort of life do you know (about)?

That's a secret only Ivan and I know about.

How would you search for it? How would you know when you found it?

At great distances, you would look for things like chemical systems that are out of balanace (like how the Earth has more methane than it should in its oxygen-rich atmosphere...thanks to Life). Or in a search for intelligent life, you would look for radio/etc. signals that cannot be explained by natural phenomena.

Or close up, you may look for mysterious chemical reactions (signs of respiration, digestion, etc.), forms that seem to resist normal erosional patterns, reductions in local entropy, etc.

But I agree a first-look is best done for things we're familiar with. Just keep in mind that if there is other life out there, our kind may be a minority. Perhaps we could broaden our search expectations to encompass more possibilities so we don't spend the $$ to look at the same planet twice.

Originally posted by Phobos
the Earth has more methane than it should in its oxygen-rich atmosphere...thanks to Life.

One of my professors made the comment that if ET were looking for us, it wouldn't be from our radio emmissions, interstellar probes, or lasers... the thing which would tip them off that we're here would be cow farts.

Originally posted by enigma One of my professors made the comment that if ET were looking for us, it wouldn't be from our radio emmissions, interstellar probes, or lasers... the thing which would tip them off that we're here would be cow farts.

Good one. I wonder if we all squeezed all the cows of the world at the right frequency, if we could send a coherent methane signal into the atmosphere which could be deciphered by ETs.

On a more serious note, like the b-flat of a black hole, it is interesting that that of the more detectable things to alien civilizations is bacterial action (in this case, in the digestive tracts of bovines)...a recurring theme that bacteria, not humans are the dominant lifeform on Earth. Not that I'm trying to promote their microbial agenda, mind you.

PhobosAt great distances, you would look for things like chemical systems that are out of balanace (like how the Earth has more methane than it should in its oxygen-rich atmosphere...thanks to Life).

We know about imbalanced atmospheric chemical systems, such as methane and oxygen, as signals for Earth-like life. So spending your precious science budget on a program to find planets and examine their atmospheres for oxygen AND methane seems reasonable (for now). Finding HFCs would be most interesting.

Finding methane, ammonia and water on a Neptune-sized planet doesn't say anything about cows

How would you go about finding non-Earth-like life?

PhobosOr in a search for intelligent life, you would look for radio/etc. signals that cannot be explained by natural phenomena.

How could you tell what's the result of a natural phenomenon and what's not?

How would you go about deciding which (non-radio) signals to look for?

and then, if you find any of those, check to see if they have
signs of bacterial life (like chemical imbalance just mentioned)

and only then, if you see a wet HZ planet with signs associated with singecell life, check for signs of a civilization

a plodding systematic approach could make you miss out on a lot like chemically exotic forms of life or civilizations of robots that fart freon instead of methane, but a plodding systematic approach might at least succeed in finding something, namely some wet HZ planets

(that's all I care about anyway, I'm horny to colonize and to hell with civilized aliens....[the rest of this message was suppressed]...

Will that be the worm-hole drive, or does Sir prefer the 'sacrifice my great-grandchildren in a sub-light speed souped-up Soyez' alternative?

Madam, I believe one of the main technical obstacles is how to program a computer to rear psychologically normal human from frozen egg in the complete absence of live humans----that is, to automate parenting. One might try first with chimpanzee babies---can one design an intelligent environment with robotic interfaces which can rear an emotionally healthy chimp from embryo without the intervention of a real-life chimp mother?

At sub-light, unmanned automatic devices could accomplish much of the colonization job including establishing lowerforms of life, but the final step----sending the information needed to reconstruct culturally recognizable humans ab ovo, seems challenging. The first babies would presumably watch a lot of video, as many do today, and it might not be good for them. Maybe one could arrange for them to have a dog.